The Saccharomyces cerevisiae Peroxisomal 2,4-Dienoyl-CoA Reductase Is Encoded by the Oleate-inducible GeneSPS19

Aner Gurvitz,Hanspeter Rottensteiner,Seppo H Kilpeläinen,Andreas Hartig,J Kalervo Hiltunen,Maximilian Binder,Ian W Dawes,Barbara Hamilton

doi:10.1074/jbc.272.35.22140

Abstract

beta-Oxidation is compartmentalized in mammals into both mitochondria and peroxisomes. Fatty acids with double bonds at even-numbered positions require for their degradation the auxiliary enzyme 2,4-dienoyl-CoA reductase, and at least three isoforms, two mitochondrial and one peroxisomal, exist in the rat. The Saccharomyces cerevisiae Sps19p is 34% similar to the human and rat mitochondrial reductases, and an SPS19 deleted strain was unable to utilize petroselineate (cis-C18:1(6)) as the sole carbon source, but remained viable on oleate (cis-C18:1(9)). Sps19p was purified to homogeneity from oleate-induced cells and the homodimeric enzyme (native molecular weight 69,000) converted 2,4-hexadienoyl-CoA into 3-hexenoyl-CoA in an NADPH-dependent manner and therefore contained 2,4-dienoyl-CoA reductase activity. Antibodies raised against Sps19p decorated the peroxisomal matrix of oleate-induced cells. SPS19 shares with the sporulation-specific SPS18 a common promoter region that contains an oleate response element. This element unidirectionally regulates transcription of the reductase and is sufficient for oleate induction of a promoterless CYC1-lacZ reporter gene. SPS19 is dispensable for growth and sporulation on solid acetate and oleate media, but is essential for these processes to occur on petroselineate.

Highlights

The ␤-oxidation auxiliary enzyme 2,4-dienoyl-CoA reductase (EC 1.3.1.34) participates in the degradation of unsaturated fatty acids with double bonds at even-numbered [1, 2] and possibly at odd-numbered positions [3, 4]
We show here that Sps19p is a peroxisomally localized 2,4dienoyl-CoA reductase and that the sps19⌬ deletant is unable to grow on petroselineate as the sole carbon source, it remains viable on oleate
Terminal residues showed that unlike its mitochondrially targeted mammalian homologues, Sps19p lacked the appropriate leader sequence and instead contained a carboxyl-terminal SKL peroxisomal targeting signal [24]. This suggested that Sps19p may be an enzyme involved in ␤-oxidation [23], since in yeast this process is restricted to the peroxisomes [18]

Summary

Introduction

The ␤-oxidation auxiliary enzyme 2,4-dienoyl-CoA reductase (EC 1.3.1.34) participates in the degradation of unsaturated fatty acids with double bonds at even-numbered [1, 2] and possibly at odd-numbered positions [3, 4]. It catalyzes an NADPH-dependent reduction of trans-2,cis/trans-4-dienoylCoA into trans-3-enoyl-CoA in eukaryotes [1] and into trans-2-. We show here that Sps19p is a peroxisomally localized 2,4dienoyl-CoA reductase and that the sps19⌬ deletant is unable to grow on petroselineate as the sole carbon source, it remains viable on oleate.

Methods

Results

Conclusion